Improvement in mariners  compasses



N. H. DIBBLE. Mariners Compass. No.l68,726. l

Patented Oct. 11, 1875.

jfl-5.1

MFETERS, PHUTO-LITHOGRAPHER. WASHINGTON, D C.

from the said pivot.

UNITED' STATEs PATENT OFFICE. N

NOAH H. l-IBBLE, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN MARINERS COMPASSES.

v Specification forming part of Letters Patent No. 168,726, dated October 11, 1875; application filed August 10, 1875.

To all whom 'it may concern:

Be it known that I, NOAH H. DIBELE, of Chicago, in the county of Cook and State of Illinois, have invented an Improved Mariners i Compass, of which the following is a specilifrom dropping oli' its pivot in case the compass should accidentally be `capsized.

The invention consists, rst, in inclosing y the binnacle-box proper in an outer watertight casing, the space between it and the former lto be filled with Water, glycerine, or other transparentliquid, the effect of which is to prevent. deviation of the needle under local attraction, the iniiuence of Which is avrrested or nullited by the inclosing duid; second, in a means for lling the compass-box with dry air or any suitable gas, to prevent the obscuring oi' its top glass by the condensation of moisture under it; third, in a means for preventing the needle-cup from rising oft' clear of its pivot. y

Figure 1 is a perspective view. Fig. 2 is a vertical section.

In the drawing, A represents an ordinary copper compass-box, hung by the gimbals a in a copper binnacle, B, the said compass-box having a central pivot, b, on which the card C is supported by the apex ofthe pivot, which enters the cup c of the needle. The compassboxfhas fitted to it an air and water tight glass cover, A', from the center of which hangs a stud, d, at a little distance above the cup c, so as to allow the latter perfect freedom of motion, but close enough to arrest it and prevent it from becoming entirely free The binnacle-box is provided with a glass cover, B', tted Water-tight thereto. D is an outer casing, which inclos'es the binnacle-boX, and is in like manner fitted With a Water-tight glass top, D. The binnacle is supported on short standards above binnacle.

space between the latter and all sides of the cle is filled with dry air or gas, such as hydro- Y geh, that will not condense to moisture, when the tube should be closed by its plug. The

space betW-een thc binnacle and its outer casing should then be filled with Water, glycerine, or other transparent fluid, and the cap E secured onto the iillingpipe E, when the compass is ready for use.

By inclosing the needle in a fluid, it is freed from the iniiuences of local attraction, and consequently will at all times be in the meridian.

What I claim as my invention is l. A mariners compass having its binnacle inclosed or immersed in a iiuid contained n anouter casing, substantially as described.

2. In a mariners compass, substantially as described, the means for iilling the binnacle with dry air or gas, consisting of the coiled pipe c, having a screw-plug, e', substantially as described and shown.

3. In a mariners compass, substantially as described, the means for filling the binnaclecasing with a iluid, consisting of the bent pipe E, having a screw-cap, E', substantially asA described and shown.

4. In a mariners compass, the stop-stud d,

pendent from the binnacle-glass, as andfor the purpose set forth. y

NOAH H. DIBBLE. Witnesses:

.WMl H. LoTz,

GEO. FEOMMANN.

E is a bent pipe tapped into one 

